public class mySigleList implements IList{
    static class ListNode{
        public int val;
        public ListNode next;

        public ListNode(int val) {
            this.val = val;
        }
    }

   public ListNode head;

    @Override
    public void addFirst(int date) {
        ListNode node=new ListNode(date);
        node.next=head;
        head=node;

    }

    @Override
    public void addLast(int date) {
        ListNode node=new ListNode(date);
        ListNode cur=head;
        if(head==null){
            head=node;
            return;
        }
        while(cur.next!=null){
            cur=cur.next;
        }
        cur.next=node;

    }

    @Override
    public void addIndex(int index,int date) {
        ListNode node=new ListNode(date);
        if(index<0||index>size()){
            System.out.println("位置不合适");
        }
        if(index==0){
            addFirst(index);
            return;
        }
        if(index==size()){
            addLast(index);
            return;
        }
        ListNode cur=head;
        while(index-1>0){
            cur=cur.next;
            index--;
        }
        node.next=cur.next;
        cur.next=node;

    }

    @Override
    public boolean contains(int key) {
        ListNode cur=head;
        while(cur!=null){
           if(cur.val==key){
               return true;
           }
           cur=cur.next;
        }
        return false;
    }

    @Override
    public void remove(int key) {
        if(head==null){
            return;
        }
        ListNode cur=head;
        while(cur.next!=null){
            if(cur.next.val==key){
                ListNode del=cur.next;
                cur.next=del.next;
            }
            cur=cur.next;
        }
        if(head.val==key){
            head=head.next;
            return;
        }
    }

    @Override
    public void removeAllKey(int key) {
        if(head==null){
            return;
        }
        ListNode prev=head;
        ListNode cur=head.next;
        while (cur!=null){
            if(cur.val==key){
                prev.next=cur.next;
                cur=cur.next;
            }else {
                prev=cur;
                cur=cur.next;
            }
        }
        if(head.val==key){
            head=head.next;
            return;
        }

    }

    @Override
    public int size() {
        ListNode cur=head;
        int count=0;
        while(cur!=null){
            count++;
            cur=cur.next;
        }
        return count;
    }

    @Override
    public void clear() {
        ListNode cur=head;
        while (cur!=null){
            ListNode curN=cur.next;
            cur.next=null;
            cur=curN;
        }
        head=null;


    }

    @Override
    public void disPlay() {
        ListNode cur=head;
        while(cur!=null){
            System.out.print(cur.val+" ");
            cur=cur.next;
        }

    }
}